1. Field of the Invention
This invention concerns a single triple or twin wiper replacement carrier and blade unit for a twin wiper unit comprising a flexible carrier formed by at least two essentially parallel struts defining a longitudinal direction, a bridge structure coupling the struts to each other in an essentially parallel relationship, two or three conventional blades extending in the longitudinal direction essentially parallel to the struts and supported by and extending downward from the carrier, and with means for removably attaching the single triple or twin wiper replacement carrier and blade unit to a twin wiper unit.
2. Description of the Prior Art
Traditionally, windshield wipers for keeping automotive windshields clear have been comprised of a single blade of resilient material, such as rubber, which is removably mounted in an arm. However, in recent years so called "twin wipers" have become popular. These kinds of wipers employ two blades which are mounted in parallel by a holder formed of a pair of parallel struts, a bridge coupling the struts, and two separate removable blades, which are identical to the blades used on conventional single blade wipers.
These twin wipers, which provide enhanced performance as well as having a distinctive "look", have been very successful. On the one hand the ability to replace the blades in twin wipers with conventional blades was convenient, particularly when twin wipers were new to the market, and insufficient demand existed for a replacement which could only be used on twin wipers. On the other hand, the unique nature of the twin wiper calls for a unique replacement which can enhance the performance and characteristics of twin wipers. Furthermore, a clear need exists for a unitary "replacement" which can also be supplied originally or not as the seller may elect.
A further development has been the so called triple wiper in which three blades can successively wipe the glass, again improving performance. In the most popular form the three blades extend from a single holder portion which is unitary and of the same material as the blades. While very popular, the blade is not readily adaptable to a twin wiper. Thus, the consumer is forced to choose between the benefits and look of a twin wiper or that of a triple wiper; he or she cannot have both.
A clear need exists for a way in which the characteristics, appearance and performance of the twin wiper can be enhanced. A separate need exists for an arrangement whereby a triple blade can be used on a conventional twin wiper.
Various wipers have been developed over the years which, while not satisfying the needs stated above, are worth reviewing to better understand the technical background from which the present invention has come.
U.S. Design Pat. No. 28,990 (CUMMING) concerns a design for a window cleaner in which a rubber filling between segmented plates of a long handled window cleaner fits between two concentric segmental plates such that both ends of the rubber filling are exposed to the window, giving a twin wiper effect. This design is not for an automobile windshield wiper but is instead for a manual window cleaner.
U.S. Pat. No. 1,370,910 (PEDERSON) is for a windshield cleaner consisting of a wiper bar of resilient material, bent backwardly at approximately right angles to provide channels for wiper strips, the outer walls of the channels terminating at about the line of the body of the wiper bar. The wiper strips are composed of any material. After the wiper strips are inserted in their channels, the side walls of the channels are pressed toward each other to effectually grip the wiper strips in position. This windshield cleaner is heavy and clumsy and does not possess individual struts, connected by bridges, which have blades extending downwardly from the struts, nor does it provide means for attaching to a twin wiper unit as a replacement for the worn out blades of the wiper unit.
U.S. Pat. No. 1,441,593 (LAVIETES) is a windshield cleaner of the type shown and described in U.S. Pat. No. 1,370,909 (PEDERSON).
U.S. Pat. No. 1,940,329 (SHIERK) is for a squeegee for windshield wipers, and consists of a sheet of rubber with a corrugated portion, bent back on itself with the ends of the rubber sheet secured in a holder having substantially parallel surfaces, each of the side walls of the legs of the holder having projections extending inwardly from the inner surface for engaging the squeegee.
Australian Patent No. 105,750 (WHATMORE) is for a windshield wiper which has a plurality --as two or three or more-- of parallel arms or holders spaced apart and each edged with one or more thin sheets of rubber or similar flexible material. Distance pieces and rivets function to space apart two identically formed wiper blade holders of channelled metal formation. Each holder has secured within its channel an edge of a strip of suitably formed flexible material such as rubber, forming a wiper blade. The holders are secured by a bridge piece which in turn has a central upright projection which is longitudinally holed and forms a connecting element whereby the two-bladed wiper unit may be loosely fitted to the end of the wiper arm. This device can not be used as a replacement wiper unit for a twin wiper unit as there are no means for attaching this unit to an existing twin wiper unit. Additionally, the wiper holders are not flexible.
U.S. Pat. No. 2,324,365 (COUTTS) is a windshield wiper in which a single sheet of metal is folded longitudinally to provide a bridge and sidewalls extending from opposite sides of the bridge and constituting blades over which can be fitted rubber shoes. This device can not be used as a replacement or refill unit for a twin wiper unit.
U.S. Pat. No 3,224,027 (OISHEI) is for a twin lipped wiper blade using double-ply construction. Neither this device nor the U.S. Pat. No. 2,324,365 is designed for a single replacement unit of the blades of a twin wiper unit.
Australian Patent Document No. 28895/89 is for a wiper refill which comprises a backing member and a blade arrangement including at least two wiping flares adapted to coact and a base arrangement including attachment means constructed and arranged for attaching the blade arrangement to the backing member. Each wiping flare may be adjacent to one another such that when in use there is defined a tubular space or void between adjacent wiping flares and the surface to be wiped. This device differs from the present invention as Australian Patent No. 3,224,027 is designed solely as a replacement for a single wiper blade.
U.S. Pat. No. 4,317,251 (PRIESEMUTH) is for a windshield wiper having two strips of rubber-like material mounted in a separate holder, one on each side of the actual wiper blade, to store and distribute a cleaning fluid over the windshield surface. This blade cannot be used as a replacement for a twin wiper unit, nor does it have the bridge and strut arrangement of the invention.
U.S. Pat. No. 4,339,839 (KNIGHTS) is for a windshield wiper comprising a carrier adapted for mounting on a windscreen wiper arm and for supporting a pair of spaced parallel wiping lips. The blade carrier has two side members and a cross member and each side member at its base may have an inwardly directed flange adapted to be accommodated in a longitudinal groove formed in a side of a blade assembly comprising the two lips and a cross member in which the device may be mounted. This device can not be used as a replacement for a twin wiper unit, nor are there struts connected by a bridge from which the blades extend downward.
U.S. Pat. No. 4,628,565 (WOLTERS) is for a windscreen wiper with at least two wiper blades. The windscreen wiper is comprised of two wiper blades and a bridge structure for coupling the wiper blades. The bridge structure is a light weight low-profiled structure and comprises two longitudinal bars which run parallel to and in the longitudinal direction of the wiper blades and are designed uncurved with respect to the wiper blades and connected to each other by cross connecting webs. While this device is an improvement over previous wiper blades systems, the wiper blade arrangement still lacks rigidity. Additionally, when the wiper blades of this device become worn or otherwise need replacing, it is necessary to carry out two operations to remove or replace both worn out blades.